Vulnerability identifier: #VU20445

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-12525

CWE-ID: CWE-119

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Squid
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor: Squid-cache.org

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input passed via the Proxy-Authorization header when Squid is configured to use HTTP Digest authentication . A remote attacker can send specially crafted HTTP request to the proxy server and perform denial of service attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Squid: 3.3.4 - 3.5.28, 4.0.1 - 4.7

---

External links
http://www.squid-cache.org/Versions/v4/changesets/
http://www.squid-cache.org/Versions/v4/changesets/squid-4-7f73e9c5d17664b882ed32590e6af310c247f320.patch
http://github.com/squid-cache/squid/commits/v4
http://lists.debian.org/debian-lts-announce/2019/07/msg00018.html
http://usn.ubuntu.com/4065-1/
http://usn.ubuntu.com/4065-2/

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.